Sunday's Argentinian MotoGP came to a dramatic climax when Valentino Rossi and reigning double champion Marc Marquez clashed on the penultimate lap.

Seven time champion Rossi, using the extra-hard rear tyre, had reeled in Marquez after the young Spaniard changed to the softer tyre on the grid and pulled an early four-second lead.

Rossi made his first pass under braking for Turn 2 on the same penultimate lap, but ran deep, allowing Marquez to cut back underneath. This had been the sector in which Marquez was losing the most time to Rossi.

At the end of the back straight Rossi again dived for the inside on the brakes, into the right-hand Turn 5 hairpin. Marquez likewise attempted to beat Rossi to the apex, just as he had successfully done a few corners before.

But Rossi controlled his braking much better this time and instead of allowing Marquez to turn across behind him, replays show Marquez was forced to hesitate and lift slightly before leaning in again (due to Rossi still being alongside, a classic block pass).

With hindsight, that turn-in delay probably scuppered Marquez's chances of re-passing Rossi at that corner. But Marquez still attempted to pass, squirting the throttle but still being half a bikelength behind when they made contact at the apex (Rossi on the outside, Marquez on the inside).

A few seconds later the pair tangled again on the exit of the corner as Rossi, leading by almost a bike length, made the transition from right to left in preparation for the left-hand corner that followed.

Marquez's front wheel was hit by Rossi's rear wheel, sending the reigning double champion tumbling down the track. Race Direction launched an investigation but soon declared it a racing incident and, from the footage, it is hard to argue otherwise.

Assumptions based on racing lines for the previous laps count for little, since the pair were now in a battle and had made an unusual corner entry, plus the contact at the apex.

Of course, having led from the start, Marquez would not have known Rossi's normal line out of Turn 5 and into Turn 6 anyway. For what it's worth, Rossi's exit line did not appear different from the lap before.

Did Rossi jink to the right too quickly? Should he have given Marquez more room? The Italian's fleeting glance to the right just before the (corner exit) contact is seen by some as proof he knew Marquez was there. Rossi denies he saw Marquez, the glance confirming that Marquez was not alongside.

"For me I think he did a mistake," Rossi said. "When I opened the throttle to accelerate, because I want to take a small advantage before the next braking, I hear another touch. But sincerely I don't know if it was on the right or left."

Marquez, who described Rossi as his idol and will therefore be aware of the perils of getting into a public argument with the seven time champion, said only: "On the final laps I went back in the low 1'39s and knew we would be fighting to the end. But when he passed me - you saw on the video what happened."

Those viewpoints were echoed by their respective team management. Yamaha's Lin Jarvis declared that Marquez was in the wrong, while Honda's Livio Suppo skipped over the specifics.

"Unfortunately Marc made a mistake. Well actually he made two mistakes," Jarvis told "Because after he was passed by Valentino he tried to come back at him too soon, too aggressive, and after the first touch then I think he should have backed off a little bit. Because clearly Valentino was faster at that stage of the race so to come back at him again and be too close Vale turned in [to Turn 6] - I'm sorry to say but it's Marc's mistake."

Suppo stated: "Race Direction said it is a racing accident. [It] can happen. We knew that with the same tyre Valentino was faster so the strategy I think was correct. The plan was to try to escape and then manage to the end. The strategy went ok until almost the end! It's a pity we didn't see a good battle between Vale and Marc, but these things can happen."

Ultimately Marquez found himself in the wrong place at the wrong time. But, baring anything reckless by the rider in front, it's up to the rider behind to avoid contact.

To put it another way, Marquez gambled that Rossi wouldn't move across and, in the words of the Italian, "Marc is a rider that always bets all-or-nothing."

Which is exactly what makes Marquez so special to watch.

Onto Jerez!